This proposal is designed to identify, characterize, and clone Mycobacterium tuberculosis genes encoding proteins associated with specific T cell responses of presumed protected humans and animals. Antigens associated with both CD4+ and/or CD8+ T cell responses are the target of this proposal. The recent identification, by our group, of a novel and protective antigen opens new possibilities for vaccine development. Two other antigens/gene have been cloned, expressed, and purified. They will be evaluated for their ability to elicit T cell responses from human PBMC, primarily from non-BCG immunized PPD+ healthy individuals. The recombinant antigens alone and in combination will also be evaluated as vaccine candidates in three animal protection models, including mice, guinea pigs, and cynomolgus monkeys, all of which will be challenged by aerosol or intratracheal routes. In addition to the evaluation of these antigens, we will characterize and clone other vaccine candidates using recently developed approaches for the direct identification of both CD4 and CD8 T cell antigens.